Article inspection device, article inspection program, article inspection system, and computer-readable storage medium

Abstract

The present invention detects a problem that is difficult to sense by using a picking robot, and updates inventory information in a warehouse system in accordance with the problem.　An article inspection device according to an embodiment comprises: a reception unit that, on the basis of an order list, receives an inspection instruction including an article ID of an article picked up by a picking robot and the weight of the article; a weight sensor that measures the weight of the article; a determination unit that determines whether a problem occurs in the article on the basis of the weight of the article included in the inspection instruction and the measured weight of the article; a generation unit that generates an inspection result corresponding to the determination; and a transmission unit that transmits the result of inspection.

Description

ARTICLE INSPECTION DEVICE, ARTICLE INSPECTION PROGRAM, ARTICLE INSPECTION SYSTEM, AND COMPUTER-READABLE STORAGE MEDIUM

[0001] An embodiment of the present invention relates to an item inspection device, an item inspection program, an item inspection system, and a computer-readable storage medium.

[0002] In recent years, digital transformation (DX) has been progressing in logistics warehouses and other facilities. As a result, various robots are working together to automate logistics tasks. For example, a picking robot picks an item from an inventory box and delivers it to a subsequent stage. However, when picking with a picking robot, there are problems that are difficult for the picking robot to detect, such as damage to the item or picking multiple items.

[0003] For example, Patent Document 1 discloses a technique for improving the work efficiency of a picking robot by utilizing operation history information of the picking robot.

[0004] Japanese Patent Application Publication No. 2020-040159

[0005] Even if the work efficiency of picking robots is improved as described in the patent document, problems such as damage to items or picking multiple items, which are difficult for picking robots to detect, still occur. When a problem occurs with a picked item, a discrepancy occurs between the number of items indicated in the inventory information held by the warehouse system and the actual number of items. As a result, even if the actual inventory is zero, the warehouse system may indicate that there is inventory, and the inventory system may issue a shipping instruction for that item.

[0006] This invention was made in light of the above circumstances, and its purpose is to provide technology that can detect problems that are difficult for picking robots to detect and update inventory information in a warehouse system in response to the problem.

[0007] The item inspection device according to the embodiment includes a receiving unit that receives an inspection instruction including the item ID of an item picked by a picking robot based on an order list and the weight of the item, a weight sensor that measures the weight of the item, a determination unit that determines whether there is a problem with the item based on the weight of the item included in the inspection instruction and the measured weight of the item, a generation unit that generates an inspection result according to the determination, and a transmission unit that transmits the inspection result.

[0008] FIG. 1 is a conceptual diagram showing an example of the arrangement of devices in an item inspection system according to the first embodiment. FIG. 2 is a block diagram showing an example of the configuration of a WCS according to the first embodiment. FIG. 3 is a block diagram showing an example of the configuration of a picking robot according to the first embodiment. FIG. 4 is a block diagram showing an example of the configuration of an inspection unit according to the first embodiment. FIG. 5 is an image diagram showing an example of an inspection operation by the item inspection system. FIG. 6 is a sequence diagram for explaining an example of an item inspection operation according to the first embodiment. FIG. 7 is a diagram showing an example of information included in an inspection instruction. FIG. 8 is a flowchart for explaining step ST105 in more detail. FIG. 9 is a diagram showing an example of information included in an inspection result. FIG. 10 is a sequence diagram for explaining an example of an item inspection operation according to the second embodiment. Embodiment

[0009] Hereinafter, an item inspection device, an item inspection program, an item inspection system, and a computer-readable storage medium will be described in detail with reference to the drawings. In the following embodiments, parts with the same numbers perform similar operations, and redundant description will be omitted. For example, when there are multiple identical or similar elements, a common symbol may be used to describe each element without distinguishing between them, or a subnumber may be used in addition to the common symbol to describe each element with distinction between them.

[0010] In the following description, the term "A or B" means at least one of A or B, and the term "A, B, or C" means at least one of A, B, or C. Furthermore, the term "A and B" also means at least one of A and B, and the term "A, B, and C" means at least one of A, B, and C.

[0011] [First embodiment] (Configuration) Fig. 1 is a conceptual diagram showing an example of the arrangement of devices in an item inspection system according to the first embodiment. As shown in Fig. 1, the item inspection system includes a warehouse operation system (WES) 1, a warehouse control system (WCS) 2, an item transport system 3, a picking robot system 4, and a sorter 5. Furthermore, the picking robot system 4 includes a picking robot 41 and an inspection unit 42.

[0012] The WES 1 can be configured with one or more general-purpose computers. The WES 30 includes a processor, a memory, and an interface. The processor is a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), or the like. The memory stores the processor's operating program, etc. The interface communicates with the WCS 2, etc. via a network.

[0013] The WES1 receives item management information such as an order list from an external device such as a host server, and transmits the received item management information to the WCS2.

[0014] The WCS 2 is composed of one or more computers, i.e., a processor, memory, and an interface. The processor is a CPU, MPU, DSP, or the like. The WCS 2 also outputs item transport instructions to the item transport system 3 based on the order list, and controls the item transport system 3. The WCS 2 also outputs picking instructions to the picking robot 41 of the picking robot system 4, and controls the picking of items by the picking robot 41. The WCS also outputs item inspection instructions to the inspection unit 42 for the picking robot 41.

[0015] An order list is a list of items stored on warehouse shelves or the like, and specifies one or more items. For example, the order list includes item information, ordering information, delivery information, etc. The order list also includes a flag indicating first-time arrival, a flag indicating that an image is not registered or that a recognition dictionary is not supported, and an item grasping success rate. Note that the flag indicating first-time arrival, the flag indicating that an image is not registered or that a recognition dictionary is not supported, and the item grasping success rate may be information held as an item database by the WCS 2, the picking robot 41, etc.

[0016] The item information includes the number of items, the item name, the item ID, whether the picking was successful, etc. The order information includes the order date and time, the orderer, etc. The delivery information includes the delivery destination, the delivery date and time, the recipient, etc.

[0017] The item transport system 3 is a system for transporting shelves or boxes, etc., arranged in a warehouse to the picking robot system 4. For example, the item transport system 3 includes an automated guided vehicle (AGV) or the like that transports shelves containing items required by the picking robot system 4 according to an order list.

[0018] The picking robot 41 is composed of one or more computers, i.e., a processor, memory, an interface, etc. The processor may be a CPU, an MPU, a DSP, etc. Under the control of the processor, the picking robot 41 communicates with the WCS 2, receives a picking instruction from the WCS 2, and, in accordance with the picking instruction, grasps an item from a shelf transported by the item transport system 3 and moves it from the grasping position to a destination position. Here, the destination position is, for example, a predetermined position where the inspection unit 42 is located. The picking instruction may simply be an instruction to start picking. In this case, based on a detection signal of an item or case arriving at the grasping position, the picking robot 41 grasps the item arriving at the grasping position or the item contained in the case and moves it from the grasping position to the destination position of the inspection unit 42.

[0019] For example, when the picking robot 41 moves an item to a predetermined position, it is difficult to detect the following problems: (1) Picking zero items (the picking robot 41 determines that it has picked an item, but in fact has not picked one) (2) Picking multiple items (3) Picking the wrong item (i.e., the wrong item) (4) Damage to the item (damaging the item during picking) (5) Dropping during transport Therefore, these problems are detected using the inspection unit 42 described below.

[0020] The inspection unit 42, which is an item inspection device, is composed of one or more computers, i.e., a processor, memory, interface, etc. The processor is a CPU, MPU, DSP, etc. The inspection unit 42 transports inspected items to the sorter 5, which is a subsequent processing stage. The inspection unit 42 recognizes the items placed on the inspection unit 42 using a sensor, camera, etc., to determine the condition of the items picked by the picking robot 41. The inspection unit 42 transmits the determined condition of the items to the warehouse control system 2.

[0021] For example, the inspection unit 42 receives item information and picking information from the picking robot 41 or the WCS 2. Then, the inspection unit 42 determines whether or not there is a problem with the item picked by the picking robot 41. Details of the method for determining whether or not there is a problem will be described later.

[0022] The sorter 5 is a sorting device that sorts the items transported by the inspection unit 42 to sorting destinations called sorting surfaces. The sorter 5 sends the items that have passed through the picking robot system 4 to the sorting destinations (sorting destinations) in accordance with sorting instructions received from the WCS 2.

[0023] Fig. 2 is a block diagram showing an example of the configuration of the WCS 2 according to the first embodiment. As shown in Fig. 2, the WCS 2 includes a processor 201, a ROM 202, a RAM 203, an auxiliary storage device 204, a communication interface 205, and the like.

[0024] The processor 201 is a CPU, an MPU, a DSP, or the like. The processor 201 operates based on a program stored in the ROM 202, or the like. The processor 201 acquires an order list, generates a picking instruction for the picking robot 41 to pick an item based on the order list, and outputs the generated picking instruction to the picking robot 41. Furthermore, the processor 201 acquires picking result information from the picking robot 41, including the results of picking the item in accordance with the picking instruction. The processor 201 then generates picking information based on the picking result information. Furthermore, the processor 201 generates an inspection instruction for the item picked by the picking robot 41, and outputs the picking information and the inspection instruction to the inspection unit 42.

[0025] The ROM 202 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 202 also stores data or various setting values ​​used by the processor 201 when performing various processes. For example, the ROM stores inventory information. The inventory information includes information such as the item IDs, number of items, item names, and item weights of items contained on shelves or boxes in the warehouse.

[0026] The RAM 203 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 201 performs various processes.

[0027] The auxiliary storage device 204 is a non-transitory computer-readable storage medium and may store the above-mentioned programs. The auxiliary storage device 204 also stores data used by the processor 201 when performing various processes, data generated by the processes of the processor 201, various setting values, and the like.

[0028] The communication interface 205 is an interface for transmitting and receiving data to and from various devices. The communication interface 205 is connected to the article conveyance system 3, the picking robot system 4, the sorter 5, etc. The communication interface 205 also acquires order lists and the like from external systems, etc. For example, the communication interface 205 supports LAN (local area network) connections, etc. The communication interface 205 may also be configured to include individual interfaces for transmitting and receiving data to and from various devices.

[0029] Fig. 3 is a block diagram showing an example of the configuration of the picking robot 41 according to the first embodiment. As shown in Fig. 3, the picking robot 41 includes a processor 411, a ROM 412, a RAM 413, an auxiliary storage device 414, a communication interface 415, a picking unit 416, etc.

[0030] The processor 411 is a CPU, an MPU, a DSP, or the like. The processor 411 operates based on a program stored in a ROM 412, or the like. The processor 411 receives a picking instruction. Then, the processor 421 picks an item using a picking means 416, which will be described later. The processor 421 then moves the picked item to a predetermined position in the inspection unit 42, which will be described later. The processor 421 may also generate a picking result including information about the picked item and transmit it to the WCS 2.

[0031] The ROM 412 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 412 also stores data and various setting values ​​used by the processor 411 when performing various processes.

[0032] The RAM 413 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 411 performs various processes.

[0033] The auxiliary storage device 414 is a non-transitory computer-readable storage medium and may store the above-mentioned programs. The auxiliary storage device 414 also stores data used by the processor 411 when performing various processes, data generated by the processes of the processor 411, various setting values, and the like.

[0034] The communication interface 415 is an interface for transmitting and receiving data to and from various devices. The communication interface 415 is connected to the WCS 2 and the like. The communication interface 415 also acquires picking information, inspection instructions, and the like from the WCS 2. For example, the communication interface 415 supports LAN (local area network) connections. The communication interface 415 may also be configured to include individual interfaces for transmitting and receiving data to and from various devices.

[0035] The picking means 416 is a device for picking items. The picking means 416 may be a general device that can pick items and move the picked items to a predetermined position, and therefore a detailed description thereof will be omitted here.

[0036] Fig. 4 is a block diagram showing an example of the configuration of the inspection unit 42 according to the first embodiment. As shown in Fig. 4, the picking robot 41 includes a processor 421, a ROM 422, a RAM 423, an auxiliary storage device 424, a communication interface 425, a conveyor 426, a flipper 427, a sensor 428, a camera 429, a code reader 430, and the like.

[0037] The processor 421 is a CPU, an MPU, a DSP, or the like. The processor 421 operates based on a program stored in a ROM 422, or the like. When the processor 421 receives an inspection instruction, it inspects the items picked by the picking robot 41 to determine whether or not there is a problem with the items. Furthermore, if the processor 421 determines that a problem has occurred as a result of the inspection, it generates an inspection result and outputs the generated inspection result to the WCS 2.

[0038] The ROM 422 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 422 also stores data and various setting values ​​used by the processor 421 when performing various processes.

[0039] The RAM 423 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 421 performs various processes.

[0040] The auxiliary storage device 424 is a non-transitory computer-readable storage medium and may store the above-mentioned programs. The auxiliary storage device 424 also stores data used by the processor 421 when performing various processes, data generated by the processes of the processor 421, various setting values, and the like.

[0041] The communication interface 425 is an interface for transmitting and receiving data to and from various devices. The communication interface 425 is connected to the WCS2 and the like. The communication interface 425 also acquires inspection instructions and the like from the WCS2. For example, the communication interface 425 supports LAN (local area network) connections and the like. The communication interface 425 may also be configured to include individual interfaces for transmitting and receiving data to and from various devices.

[0042] The conveyor 426 is where the picking robot 41 places the items, and an inspection process is performed on the items as they move along the conveyor 426. If the inspection process finds no problems with the items, the conveyor 426 moves the items to the sorter 5, which is a subsequent device.

[0043] The flipper 427 is a sorter that, if an item is found to have a problem as a result of the inspection process, sends the item into a reject box instead of sending it to the sorter 5. Note that the flipper 427 is not necessarily an essential component. For example, if the sorter 5 is equipped with a sorter for sending items to the reject box, the flipper 427 may be omitted.

[0044] The sensor 428 includes a weight sensor 4281, a proximity sensor 4282, and the like.

[0045] The weight sensor 4281 is a sensor for measuring the weight of the items flowing on the conveyor 426. For example, the measured weight of the items is used to determine whether or not there is a problem with the items, such as zero items being picked up, multiple items being picked up, the wrong item being picked up, the item being damaged, or the item being dropped.

[0046] The proximity sensor 4282 is a sensor for determining whether or not an article is flowing on the conveyor 426. The proximity sensor 4282 is used to determine whether or not a problem such as zero pick-up or a dropped article has occurred.

[0047] The camera 429 photographs the conveyor 426 and acquires a photographed image. The camera 429 may be a general camera. The photographed image by the camera 429 is used to determine whether or not a problem has occurred with the product, such as multiple items being picked up, damage to the product, or a dropped product.

[0048] The code reader 430 is a reader for reading code information from a code (one-dimensional code, two-dimensional code, or RFID) attached to the top or side of an item when the picking robot 41 moves the item onto the conveyor 426. The code information may include at least one of an item ID and an item name. It goes without saying that the code information is not limited to an item ID and an item name, and may include any information that can identify the item. Therefore, the code information read by the code reader 430 is used to determine whether there is a problem with the item, such as the wrong item.

[0049] The inspection unit 42 does not necessarily have to include the proximity sensor 4282, the code reader 430, and the camera 429. The information acquired by these is information for further improving the accuracy of inspection by the inspection unit 42, and is not necessarily an essential component.

[0050] (Operation) Next, the inspection operation by the inspection unit 42 according to the first embodiment will be described. FIG. 5 is an image diagram showing an example of the inspection operation by the item inspection system. As shown in (1) of FIG. 5, the picking robot 41 picks up an item transported by the item transport system 3 and moves it to a predetermined position. Then, as shown in (2), the inspection unit 42 inspects the item picked by the picking robot 41 using, for example, a weight sensor 4281. As shown in (3), the inspection result is transmitted. For example, the inspection result may be transmitted when a problem has occurred. As shown in (4), if the inspection result shows no problem, the item on the conveyor 426 is transported to the sorter 5, which is a subsequent device. On the other hand, if the inspection result shows a problem, the inspection unit 42 uses the flipper 427 to sort the item into the reject box 6.

[0051] 6 is a sequence diagram illustrating an example of an inspection operation for an item according to the first embodiment. This sequence is realized by the processor 201 of the WCS, the processor 411 of the picking robot 41, and the processor 421 of the inspection unit 42 reading and executing programs stored in the ROM 202, ROM 412, and ROM 422, respectively.

[0052] First, the operation of this sequence is started when the item transport system 3 transmits to the WCS 2 information indicating that a shelf containing an item to be picked by the picking robot 41 has been transported.

[0053] In step ST101, the processor 201 of the WCS2 outputs a picking instruction to the picking robot 41. The processor 201 creates a picking instruction that instructs the picking robot 41 on the items to be picked based on the order list, and outputs the created picking instruction to the picking robot 41.

[0054] In step ST102, the processor 411 of the picking robot 41 that has received the picking instruction uses the picking means 416 to pick the item in accordance with the picking instruction. Then, the processor 411 moves the item picked using the picking means 416 to a predetermined destination position on the conveyor 426 of the inspection unit 42. The processor 411 may generate a picking result including an item ID and the like related to the picked item, and transmit the generated picking result to the WCS 2.

[0055] In step ST103, the code reader 430 acquires code information of the item from the code (one-dimensional code, two-dimensional code, or RFID) attached to the item. When the picking robot 41 places the item in a predetermined position, the code reader 430, under the control of the processor 421, reads the code information from the code attached to the top or side of the item.

[0056] In step ST104, the processor 201 outputs an inspection instruction. Upon receiving the picking result from the picking robot 41, the processor 201 creates an inspection instruction for inspecting the item picked by the picking robot 41, and outputs the inspection instruction to the inspection unit 42. Note that the processor 201 may generate an inspection instruction immediately after outputting the picking instruction to the picking robot 41, and send the inspection instruction to the inspection unit 42. In this case, step ST104 is performed after step ST102 or in parallel.

[0057] FIG. 7 is a diagram showing an example of information included in an inspection instruction. As shown in FIG. 7, the inspection instruction includes information in the key column, namely, message ID, item ID, weight, and Jancode. Furthermore, type indicates the data type. The message ID is the ID of the inspection instruction and is used to link it to the transmission of the inspection results. The item ID is an item ID managed by the WCS 2 or the like, and indicates the ID of the item picked by the picking robot 41. The Jancode includes code information, namely, at least one of the item ID and the item name.

[0058] Returning to FIG. 6, in step ST105, the processor 421 inspects the item.

[0059] 8 is a flowchart illustrating step ST105 in more detail. In step ST201, the processor 421 determines whether the code information matches. The processor 421 compares the code information read from the item with the code information included in the Jancode included in the inspection instruction, and determines whether the code information matches. For example, the processor 421 determines whether the item name included in the read code information matches the item name included in the Jancode. If they match, the process proceeds to step ST202. On the other hand, if they do not match, the processor 421 determines that an incorrect item problem has occurred. Then, the process proceeds to step ST207.

[0060] In step ST202, the processor 421 starts tracking the item. The processor 421 starts tracking the item using the camera 429. The processor 421 may also start tracking the item using the proximity sensor 4282 in parallel with or instead of tracking using the camera 429.

[0061] In step ST203, the processor 421 determines whether there is an item on the conveyor 426. The processor 421 determines whether there is an item on the conveyor 426 based on the image captured by the camera 429. For example, if an item cannot be detected on the conveyor 426, the processor 421 determines that a zero-item picking problem has occurred. Note that "not being able to detect" refers to, for example, a case where an item cannot be detected for a predetermined period of time and a timeout occurs. Furthermore, the processor 421 may determine that a multiple-item picking problem has occurred if there are multiple items on the conveyor 426. Furthermore, if it is determined that an item on the conveyor 426 is damaged based on the captured image, the processor 421 may determine that an item damage problem has occurred. In these cases, the process proceeds to step ST207.

[0062] On the other hand, if it is determined that no problem has occurred, that is, if it is determined that there is an article on the conveyor 426 that has no problem, the process proceeds to step ST204.

[0063] In step ST204, the processor 421 operates the conveyor 426. The processor 421 operates the conveyor 426 to move the article to the location where the weight sensor 4281 is installed. At this time, the processor 421 may repeatedly perform the process performed in step ST203. That is, the processor 421 may repeatedly determine whether or not there is an article on the conveyor 426.

[0064] In step ST205, it is determined whether the weight of the item is correct. For example, the processor 421 acquires the measurement result of the weight of the item by the weight sensor 4281. The processor 421 then compares the measurement result with the weight of the item included in the inspection instruction to determine whether the weight of the item is correct. If the weights differ, such as if the weight of the item is approximately two or more integral multiples of the weight of the item included in the inspection instruction, the processor 421 determines that a problem has occurred with multiple items being picked up. If the measurement result is zero and the proximity sensor 4282 cannot detect the item, the processor 421 determines that a problem has occurred with zero items being picked up or an item being dropped. Alternatively, if the bottom of the item is missing and the weight of the measurement result differs from the weight of the item included in the inspection instruction, the processor 421 determines that the item is damaged or the wrong item has been picked up. In these cases, the process proceeds to step ST207. On the other hand, if it is determined that the weight of the item is correct, the process proceeds to step ST206.

[0065] In step ST206, the processor 421 determines that the inspection has passed. The processor 421 generates an inspection result indicating that the inspection has passed.

[0066] In step ST207, the processor 421 determines that the inspection has failed, and generates an inspection result according to the problem that has occurred.

[0067] Here, the processes of steps ST201 to ST203 do not have to be performed. As described above, the code reader 430 and the camera 429 are not essential components, so if the inspection unit 42 does not include these devices, the above processes do not have to be performed.

[0068] 6, if it is determined in step ST105 that the item has passed inspection, then in step ST106, the item is moved to the sorter 5. For example, the processor 421 moves the conveyor 426 to move the item to the sorter 5.

[0069] In step ST107, the processor 421 outputs a sorting request to the sorter 5. If the inspection unit 42 and the sorter 5 are able to communicate, the processor 421 transmits the sorting request to the sorter 5 via the communication interface 425. Alternatively, if the inspection unit 42 and the sorter 5 are not able to communicate, the processor 421 generates a code (one-dimensional code or two-dimensional code) including the sorting request and displays it on a display or the like. For example, the sorter 5 reads the sorting request from the code using a code reader or the like.

[0070] If it is determined in step ST105 that the item has failed inspection, the processor 421 controls the flipper 427 to move the item to the reject box 6 in step ST108.

[0071] In step ST109, the processor 421 outputs the inspection result created in step ST206 or ST207 to the WCS 2.

[0072] 9 is a diagram showing an example of information included in the inspection result. For example, if the inspection is determined to be successful in step ST206, the inspection result includes the message ID and id0 included in the inspection instruction. On the other hand, if the inspection is determined to be unsuccessful in step ST207, the inspection result includes the message ID included in the inspection instruction and an id corresponding to the determined problem.

[0073] Also shown in FIG. 8 is a sensor 428 or camera 429 that can determine the problem in question.

[0074] 8 and described above, a zero-item extraction problem can be determined by the camera 429, or the weight sensor 4281 and the proximity sensor 4282. A multiple-item extraction problem can be determined by the weight sensor 4281 or the camera 429. A wrong-item problem can be determined by the code reader 430 or the weight sensor 4281. A damaged item problem can be determined by the weight sensor 4281 or the camera 429. Furthermore, a dropped item problem can be determined by the weight sensor 4281 and the proximity sensor 4282, or the camera 429.

[0075] 6, in step ST110, the processor 201 performs processing according to the inspection result. For example, if the inspection result is any of id2 to id4, the processor 201 corrects the inventory information and, if necessary, outputs an instruction to the item transport system 3 to redeliver the item. Alternatively, if the required item is on the shelf, the processor 201 may output a picking instruction to the picking robot 41.

[0076] Furthermore, if the inventory information is corrected so that the required number of items is zero and the item cannot be shipped, WCS2 may call an attendant to process the slip information and the like.

[0077] If the inspection result is id5 or id6, i.e., if the item is damaged or dropped, the processor 201 outputs a redelivery command to the item delivery system 3. Alternatively, if the required item is available on the shelf, a picking command may be output to the picking robot 41. Unlike id2 to id4, if the inspection result is id5 or id6, i.e., if the item is damaged or dropped, the processor 201 does not modify the inventory information, but simply determines that an additional damaged item needs to be picked, and outputs a picking command or the like to the picking robot 41. Note that the dropped item may be picked up by a worker and stored at any time.

[0078] It should be noted that steps ST109 and ST110 do not need to be performed if the inspection result is successful, because these processes are performed to correct inventory information.

[0079] (Operational Effects of the First Embodiment) According to the first embodiment described above, inspection by the inspection unit 42 can determine whether a problem has occurred that is difficult for the picking robot 41 to detect. Furthermore, if a problem has occurred with an item, the WCS 2 can correct the inventory information, thereby preventing a situation in which the inventory information differs from the actual inventory.

[0080] Second Embodiment In a second embodiment, an example will be described in which an article in which a problem has occurred is moved to the picking robot 41 side, and the picking robot 41 performs a reject process.

[0081] (Configuration) The configuration of the inspection system in the second embodiment is the same as that of the first embodiment. Therefore, a duplicated description will be omitted here. However, in the second embodiment, if an item is found to have a problem as a result of the inspection process, the conveyor 426 can reverse its rotation and return the item to the picking robot 41. Alternatively, the conveyor 426 may include a conveyor (second conveyor) different from the conveyor that moves the item to the sorter 5. For example, if an item is found to have a problem as a result of the inspection process, the second conveyor can return the defective item to the picking robot 41. In this case, the flipper 427 may move the item from the conveyor 426 to the second conveyor.

[0082] 10 is a sequence diagram illustrating an example of an inspection operation for an item according to the second embodiment. This sequence is realized by the processor 201 of the WCS, the processor 411 of the picking robot 41, and the processor 421 of the inspection unit 42 reading and executing programs stored in the ROM 202, ROM 412, and ROM 422, respectively.

[0083] The operations of steps ST301 to ST308 are the same as the operations of steps ST101 to ST107 and step ST109 described with reference to Fig. 6. Therefore, a duplicated description will be omitted here. Note that, as in the first embodiment, the inspection result of step ST308 does not need to be performed.

[0084] If the item is determined to have failed inspection in step ST305, in step ST309, the processor 421 moves the conveyor 426 to a predetermined position where the picking robot 41 places the item. For example, the processor 421 reverses the rotation of the conveyor 426 to move the conveyor 426 to the predetermined position where the picking robot 41 placed the item. Alternatively, the processor 421 moves the item to a second conveyor using a flipper 427 or the like, and moves the second conveyor to the predetermined position. Note that in this embodiment, the predetermined position may be any position where the picking robot 41 can pick the item.

[0085] In step ST310, the picking robot 41 performs a reject process. For example, the processor 421 outputs a picking instruction to the picking robot 41. Alternatively, the processor 421 outputs the picking instruction to the picking robot 41 via the WCS 2. The picking robot 41 performs a reject process in accordance with the picking instruction. The reject process differs depending on the problem contained in the inspection result.

[0086] For example, if the problem was picking zero items, the picking robot 41 picks an item from the shelf again. If the problem was picking multiple items, the picking robot 41 picks items from the multiple items on the conveyor 426 so that the correct number is picked. If the problem was picking the wrong item, the picking robot 41 returns the item on the conveyor 426 to the shelf and picks the correct item. If the item is damaged, the picking robot 41 moves the item to the reject box 6. Note that if the problem was a dropped item, the reject process does not need to be performed.

[0087] After step ST310, the inspection unit 42 may perform the inspection process of step ST305 again. If the inspection passes, the process proceeds to step ST306.

[0088] In step ST311, the processor 421 outputs inventory correction information to the WCS 2. The processor 421 generates inventory correction information according to the reject process and outputs the generated inventory correction information to the WCS 2. The inventory correction information includes, for example, a request to re-pick the item in the case of a dropped item or a damaged item. Furthermore, in the case of zero picking, multiple picking, or incorrect item picking, the correct item will be placed in the inspection unit 42 by the reject process, so the processor 421 does not need to generate inventory correction information.

[0089] In step ST312, the processor 201 performs processing according to the inventory correction information. The processor 201 corrects the inventory information based on the inventory correction information, and outputs an instruction to the item transport system 3 to redeliver the item as necessary. Alternatively, if the required item is available on the shelf, a picking instruction may be output to the picking robot 41.

[0090] Furthermore, if the inventory information is corrected so that the required number of items is zero and the item cannot be shipped, WCS2 may call an attendant to process the slip information and the like.

[0091] (Effects of the Second Embodiment) According to the second embodiment described above, defective items are returned to the picking robot 41, and the picking robot 41 performs reject processing. This makes it possible to resolve problems such as incorrect items, zero picking, and multiple picking. This eliminates the need for a person to repair items from the reject box 6. Furthermore, it is possible to reduce the problem of insufficient inventory that prevents items from being shipped because an item has been placed in the reject box 6.

[0092] [Other Embodiments] In the above-described embodiment, an example in which the inspection unit 42 is provided between the picking robot 41 and the sorter 5 has been described, but this is not limiting. This embodiment can be implemented, for example, by placing the inspection unit 42 between any devices. For example, it can also be applied to a case in which the inspection unit 42 is placed between the sorter 5 and the items being transported to a work area for packaging.

[0093] The program according to this embodiment may be transferred in a state where it is stored in an electronic device (computer) such as the WCS2 or the inspection unit 42, or may be transferred in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network or in a state where it is stored in a storage medium. The storage medium is a non-transitory, tangible medium. The storage medium is a medium that can be read by a computer such as the WCS2 or the inspection unit 42 (a computer-readable medium). The storage medium may be in any form, such as an optical disk (e.g., a CD-ROM), a magnetic disk, or a semiconductor memory (e.g., a memory card), as long as it is capable of storing a program and is readable by a computer.

[0094] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

Claims

1. An item inspection device comprising: a receiving unit that receives an inspection instruction including an item ID of an item picked by a picking robot based on an order list and the weight of the item; a weight sensor that measures the weight of the item; a determination unit that determines whether a problem has occurred with the item based on the weight of the item included in the inspection instruction and the measured weight of the item; a generation unit that generates an inspection result according to the determination; and a transmission unit that transmits the inspection result.

2. The item inspection device of claim 1, wherein if the measured weight of the item differs from the weight of the item included in the inspection instructions, the judgment unit judges that a problem has occurred, such as the item being picked in error or the item being damaged.

3. The item inspection device of claim 1, further comprising a proximity sensor for detecting the item, and when it is determined that the weight of the item measured by the weight sensor is zero and the item cannot be detected by the proximity sensor, the determination unit determines that a problem has occurred, that the item has been dropped or that the item has not been picked by the picking robot.

4. The item inspection device of claim 1, further comprising a camera that photographs the item, and the determination unit determines, based on the image of the item photographed by the camera, that a problem has occurred, such as the item not being picked by the picking robot, multiple items being removed, the item being damaged, or the item being dropped.

5. The item inspection device of claim 1, further comprising a code reader that reads code information including at least one of the item name and item ID from a code affixed to the item, and wherein the determination unit determines whether the item name or item ID included in the inspection instruction matches the item name or item ID included in the code information, and if they do not match, determines that a problem has occurred in which an item has been picked in error.

6. An item inspection device as described in any one of claims 1 to 5, further comprising a flipper for sorting the item into a reject box when the determination unit determines that a problem has occurred with the item.

7. An item inspection device as described in any one of claims 1 to 5, further comprising: a conveyor that returns the item to the picking robot when the determination unit determines that a problem has occurred with the item; a generation unit that generates instructions for causing the picking robot to perform a reject process according to the problem; and a transmission unit that transmits the instructions.

8. The item inspection device described in claim 7, wherein the conveyor is a conveyor that moves the item to a subsequent device when the judgment unit judges that there is no problem with the item, and when returning the item to the picking robot, the conveyor is rotated in the reverse direction to return the item.

9. The item inspection device according to claim 7, further comprising a second conveyor different from the conveyor, which moves the item to a subsequent device if the determination unit determines that there is no problem with the item.

10. An item inspection program executed by a processor of an item inspection device, comprising: receiving an inspection instruction including an item ID of an item picked by a picking robot based on an order list and the weight of the item; measuring the weight of the item; determining whether or not a problem has occurred with the item based on the weight of the item included in the inspection instruction and the measured weight of the item; generating an inspection result according to the determination; and transmitting the inspection result.

11. An item inspection system comprising: a picking robot; and an item inspection device that inspects items picked by the picking robot, wherein the picking robot comprises a picking means that picks an item according to a picking instruction and moves the picked item to a predetermined location of the item inspection device, and the item inspection device comprises: a receiving unit that receives an inspection instruction including an item ID of the item and a weight of the item; a weight sensor that measures the weight of the item; a determination unit that determines whether a problem has occurred with the item based on the weight of the item included in the inspection instruction and the measured weight of the item; a generation unit that generates an inspection result according to the determination; and a transmission unit that transmits the inspection result.

12. A non-transitory computer-readable storage medium storing a program executed by a processor, the computer-readable storage medium causing the processor to perform the following operations: receive an inspection instruction including an item ID of an item picked by a picking robot based on an order list and the weight of the item; measure the weight of the item; determine whether a problem has occurred with the item based on the weight of the item included in the inspection instruction and the measured weight of the item; generate an inspection result according to the determination; and transmit the inspection result.

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